A gas turbine engine utilizes numerous and various sealing systems designs to restrict the flow of fuels, oils, and gases within the turbine engine system, its modules, and its components. A gas turbine engine generally includes, in serial flow order, a low pressure (LP) compressor, a high pressure (HP) compressor, a combustion section, a HP turbine, and a LP turbine. A HP shaft couples the HP turbine to the HP compressor. An LP shaft extends coaxially within the HP shaft and couples the LP turbine to the LP compressor.
Each shaft rotates on a number of bearings located generally at a forward end and an aft end of each shaft. Bearings are generally a component of an assembly that includes lubrication systems, dampeners, and sealing systems to restrict the interchange of fluids from bearing compartments and the rotating structure.
Additionally, within the rotating structure and the turbine engine gas path, a number of various seals are employed to restrict the interchange of high pressure and high temperature fluids from low pressure and low temperature sections. Seals are also employed to keep fluids within the gas path rather than migrating to other cavities and compartments within the engine.
However, the challenge of restricting fluid interchange and migration is a function of the type of fluid, pressure and temperature, and geometric constraints between the areas to be sealed. Furthermore, weight and dimensional packaging further limit design options for sealing systems, including by dictating or constraining the geometry of an adjacent sealing surface. Where a high pressure fluid is to be segregated from a low pressure fluid in an apparatus in which a centerbody may move parallel to the centerline of a surrounding liner, such as a piston in a cavity, the use of a piston seal may alone necessitate a cylindrical cavity with an inner surface onto which a piston seal may operate.
For example, a high pressure fluid within and around a combustor necessitates a sealing system to restrict fluid interchange with a downstream low pressure cavity of a turbine section. Conventionally, piston ring seals are employed to restrict fluid interchange. However, piston ring seals require a cylindrical sealing surface, of which may add material, weight, axial length, or other design features that reduce engine efficiency, reduce component structural life, or increase the risk of defects, and thereby increase associated costs of manufacturing and maintenance.
Therefore, a sealing system for restricting the fluid interchange of a high pressure fluid and a low pressure fluid capable of overcoming the above complexities would be useful.